Biodiesel fuel is typically produced via transesterification, by reacting various plant and animal oils and fats with low molecular weight alcohols (e.g., methanol, ethanol). Often, the transesterification reaction is catalyzed by adding bases (e.g., NaOH, KOH) to the alcohol, and, using an excess amount of alcohol. Batch production processes often include mixing the oil or fat, the alcohol, and the catalyst in a large reaction tank. After a sufficient reaction time has passed, the biodiesel fuel that is produced is separated from the other reaction product (e.g., glycerol) and the unreacted starting materials (e.g., alcohol and catalyst).
The use of existing processes and systems, however, can result in undesirably long reactions times to substantially complete the transesterification reaction, or, can have unacceptably high inputs of energy to speed up the reaction. Existing processes and systems can also require an undesirably long time to separate the biodiesel fuel from the other reaction products and the unreacted starting materials.
Accordingly, what is needed in the art is a biodiesel fuel production method and system that does not suffer from the disadvantages associated with conventional methods, as discussed above.